Time's Techland points out some interesting statistics that many of us didn't know about Apple's iPad and iPhone devices: it costs less than $2 USD a year in electricity to charge. Of course, depending on where you live, and how hands-off your state government is in regulating your local utility company that cost might be slightly higher or lower.
According to research from Electric Power Research Institute, a non-profit research and development group funded by the country's electric utility companies, the annual cost to charge an iPad is $1.36 and even less for other iOS devices such as the iPhone or iPod touch. By comparison a 60-watt compact fluorescent bulb costs $1.61, a desktop PC costs up to $28.21 annually and a refrigerator runs you $65.72.
The group tackled the iOS devices to see if they would have any adverse affect on power usage in the United States. They came to the conclusion that using your favorite Apple device won't have much net effect on power consumption. And as more people use these kinds of devices for popular activities like watching TV and movies, that means less usage on devices that gobble up power like high definition television sets, cable set top boxes and PC's.
The EPRI's Baskar Vairmohan conducted the iOS research for the group to see if the growing usage of tablet devices is adding to power consumption. For the test, Vairmohan measured the amount of power used to charge up an iPad with a drained battery. He assumed that most users would charge their device every other day. The test determined that the latest version of the iPad consumed 11.86 kilowatt-hours of electricity a year. The electricity needed to charge the device would cost $1.36 at the U.S. average residential price of 11.49 cents per kilowatt-hour.
EPRI also came to the conclusion that it costs just 38 cents to charge an iPhone 4 for one year.